timer-examples

Timer Examples

This example shows how to use sleep to:

• Send a notification to the customer if their order is taking longer than expected: src/workflows.ts
• Create an UpdatableTimer that can be slept on, and at the same time, have its duration updated via Signals: src/updatable-timer.ts

Testing

Test with time skipping: npm test runs src/test/workflows.test.ts.

Running the sample

1. temporal server start-dev to start Temporal Server.
2. npm install to install dependencies.
3. Optional: Set up an account with Mailgun and create a .env file with the following environment variables: MAILGUN_API, MAILGUN_DOMAIN, and ADMIN_EMAIL. ADMIN_EMAIL is the email address your Mailgun emails will be sent to. You can use the .env.example file as a template.
4. npm run start.watch to start the Worker.

Email notification

In another shell, enter npm run workflow-slow to run the Workflow. The Workflow should return:

Order completed!

And the Worker should log (in the first shell):

Sending email: Order processing is taking longer than expected, but don't worry—the job is still running!

If we run npm run workflow-fast, then the Worker shouldn't send an email.

Updatable Timer

Run npm run workflow-updating to demonstrate the Updatable Timer.

This example shows how to write reusable libraries that encompass Workflow APIs.

countdownWorkflow is originally set to resolve after 1 day; however, the Workflow sends in a setDeadlineSignal that updates it to resolve in 1 second, and it does. You can see each step in the Worker log output, as well as the Temporal Web Timer settings.

[countdownWorkflow(6c0c152b-aead-4b1a-acf0-17e809acf0fc)] timer set for: Tue Nov 02 2021 03:03:57 GMT-0700 (Pacific Daylight Time)
[countdownWorkflow(6c0c152b-aead-4b1a-acf0-17e809acf0fc)] timer now set for: Mon Nov 01 2021 03:03:50 GMT-0700 (Pacific Daylight Time)
[countdownWorkflow(d0a3cb4d-05b1-4cfa-af25-c9223fd34140)] countdown done!